The invention relates generally to an opening means on a parallelepipedic package or carton for pourable material. The package or carton, has four side walls, a bottom and a top end wall formed of a multi-layered carrier material such as cardboard which is coated on both sides with plastic material, and at least one longitudinal sealing seam. The sealing seam extends into a pouring spout, in at least one side wall. The package or carton also has at least one transverse sealing seam in the bottom or the top wall. The package or carton is provided on two sides with double triangular-panel flaps each having inclined stamped or embossed lines. The base of the flap is formed by an end stamped or embossed line. The interior of the flap communicates, along the base, with the interior of the package or carton, to form the pouring spout. The pouring spout can be made operative by tearing open along a perforated line extending through both layers or plies of the triangular panel flap. The perforated line begins at a starting point under the front tip of the pouring spout crosses the end embossed or stamped line, and terminates approximately in the middle of the top wall.
Parallelepipedic packages or cartons for milk or juices, of that kind, are known, which are opened by a procedure wherein one of two triangular flaps is folded downwardly on to a side wall and is there secured in position. The flap is released, lifted up into the plane of the top end wall and pressed flat, whereupon for example a pair of scissors may be used to make a straight cut across the tip of the triangular flap, to form the pouring spout. An effort has been made to provide opening means for liquid carrying cartons of that kind, which do not require a separate tool which in many cases is not available to the final consumer.
To provide an opening means for such a package, it is also already known to provide a perforated line which obviously must be formed in the packaging material (plastic-coated cardboard) in such a way that the cardboard nonetheless still remains fluid-tight. A fluid-tight perforation of this type is achieved by applying a cover strip in the form of a plastic film to the perforated region on the interior of the package wall. It will be appreciated that such a sealing arrangement is expensive, due to the separate material used or the additional step required to be performed. It is undesirable for that reason.
When making an opening cut or when providing one of the known perforated lines, it is desirable for the initial cut at the front lower starting point to be arranged, approximately in the middle of the lower triangular panel of the flap at such an inclined angle that the starting point for the cutting operation is as high as possible and as close as possible to the transverse sealing seam. The reason for this arrangement is to give the maximum size of head space or air space above the level of liquid in the package, directly after the package is opened. If such arrangement were not provided the liquid would run out of the opening as soon as the first cut were made.
If the longitudinal sealing seam extends along the side wall, in the vicinity of which the triangular panel flap is disposed, that is to say, if the longitudinal sealing seam extends into what subsequently forms the pouring spout, a cut or tearing line is formed which extends across the longitudinal seam at a more or less inclined angle and which extends in an essentially linear configuration. The consequence of this configuration is that the outer, lower starting point from which the cutting action or the tearing operation begins takes up a position which is comparatively high beside the front tip portion of the pouring spout. The disadvantage of this arrangement is that the material flow follows the cut or tear line, along the line which crosses the longitudinal sealing seam, so that the material flow is not formed and guided solely by the front tip portion of the pouring spout. Consequently, the liquid spills or dribbles, because a part of the material flow comes away from the edge at the lower starting point. This result is undesirable. Hitherto, no way of overcoming this disadvantage has been found. The use of a steeper angle would result in the general configuration of the perforated or cut line being inclined excessively downwardly. Furthermore when the material is poured out of the package, there would not be the necessary air space above the level of material therein. ln addition, the rearward end of the line for tearing off or cutting off the triangular tip portion for forming the pouring spout would be disposed so far forwardly towards the top of the pouring spout that, when pouring out the material, it would not be possible for sufficient air to flow into the carton, to provide for compensation of the volume of liquid discharged therefrom. This results in a poor pouring effect because the material flow begins to pulse. The consumer refers to this condition as the material "slopping out of the carton".
The object of the present invention is therefore to provide opening means on a parallelepipedic package or carton of the kind set forth above, which makes it possible to provide a sufficiently large head space or air space on the one hand, and to provide an air entry space at the rearward end of the pour spout defined by the cut or the line on the other hand, but principally to avoid having the starting point of the spout being at an excessively high position, so that the material can actually flow in a precisely controlled manner over the front tip portion of the pouring spout and the adjacent edges thereof.